Construction notes for Ruddigore:

Lay platform nearest Green Room first; check door clearance.

Use the 4x6 1/2 for one of the 4x6 platforms.

For back steps, use 28" steps resting on 3x4 platforms to get required
height. 

Hang opaque black muslin behind scrims so noone can see through them; this can
be unpinned before ghost scene.

Most act I flats hang by hooks along their top edge from the Act II flats.
Freestanding ones should have collapsible jacks.

Scene change should probably happen by removing the door to Rose's house and
moving flats through the center-stage opening.  Afterward, place the center
portrait and back it with a flat.  (Is there enough room through here?)

The slashed lines in the alcoves downstage left and right are curtains.  Actors
push them aside to get through.

There's a curving staircase leading from the center-stage platform to the
gallery wings left and right.  It consists of a 4'x4' triangle platform
standing on the centerstage platform (its backstage leg is long enough to reach
the floor); there's a 2sqrt(2)x2sqrt(2) triangle platform sitting on it with
its 4' hypotenuse flush with the 4x8 platform toward the wings.  Make sure
everything's screwed down to the thing it's sitting on.

The 42"h platforms are rather too high to be wood construction: it's probably
most efficient to use Dexion supports here.  We need 4 4' sections, 8 42"
sections, and various short stiffeners.

The 6x8 doorway flats for the secondary portraits should be constructed of
two 1 1/2'x8' flats and one 3'x1' flat.  We have a 1x3 somewhere.  See the note
below.

Potential problems:

6" difference between top of upper platform flats and ground flats.  Use luan
wedge to smooth the jag

Not enough room in portrait header to put lighting.  Make higher, rounded
header above portrait.

Fireplace flats not wide enough?  (would need to build new ones)